The extinction of the Australian megafauna and its cause has been the topic of debate for quite some time.
According to a new study, the megafauna, which became extinct nearly 45,000 years ago, vanished not because of climatic changes — as previously believed — but because of human hunting.
"The debate over megafaunal extinction causes has consistently been between climate and humans. Having eliminated climate as the primary cause of extinction, we turn to consideration of human causation, of which hunting is most favoured as extinction driver," notes the abstract of the research.
The cause for the extinction of the Australian megafauna, which comprises quite a few creatures, has been attributed to climate shift. The landscape in southwestern Australia changed from arid to a woody one nearly 70,000 years ago. Some believe that the animals were unable to adapt and therefore died.
The other school of thought is that early immigrants hunted the megafauna when they colonized Australia. Researchers also believe that it could be a combination of both the theories.
The Findings Of The Research
The research, which was led by the Monash University in Victoria, Australia, and the University of Colorado Boulder, used data from a sediment core in the Indian Ocean. This information aided the team in recreating the older climatic conditions of the continent.
There were chronological layers of a brown-colored material, which were washed into the ocean. It also contained dust, ash, spores, and pollen from a fungus dubbed Sporormiella.
Professor Gifford Miller, who was part of the research team, shared that the Sporormiella fungus grows on the waste of plant-eating mammals.
Miller further added that the sediment core allowed the researchers to travel back in time. In this case, it took them back 15,000 years.
"The abundance of these spores is good evidence for a lot of large mammals on the southwestern Australian landscape up until about 45,000 years ago," said Miller.
Australian Megafauna
The giant kangaroo with a body weight of up to 529 pounds walked instead of hopped, alongside with the 4,000-pound wombats and a 6.56-feet-tall bird, which have all become extinct.
Miller also scrutinized the burned eggshells of the 400-pound bird Genyornis in 2016, which further asserts that human hunters were the main reason behind the disappearance of the megafuana.
It has always been a debatable issue whether human hunting or climate change are to be cited as possible reasons for the extinction of the Australian megafauna. The study led by the two universities has finally proven that the demise started due to instances of human overkilling and not because of adverse climatic conditions.
The study has been published in the journal Nature Communication on Jan. 20.
